package com.atguigu.gulimall.product.service.impl;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;
import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryBrandRelationService;
import com.atguigu.gulimall.product.service.CategoryService;
import com.atguigu.gulimall.product.vo.Catelog2Vo;
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.StringUtils;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

//    @Autowired
//    CategoryDao categoryDao;

    @Autowired
    CategoryBrandRelationService categoryBrandRelationService;

    @Autowired
    StringRedisTemplate redisTemplate;

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {
        //1、查出所有分类
        List<CategoryEntity> entities = baseMapper.selectList(null);

        //2、组装成父子的树形结构

        //2.1）、找到所有的一级分类
        List<CategoryEntity> level1Menus = entities.stream().filter(categoryEntity ->
             categoryEntity.getParentCid() == 0
        ).map((menu)->{
            menu.setChildren(getChildrens(menu,entities));
            return menu;
        }).sorted((menu1,menu2)->{
            return (menu1.getSort()==null?0:menu1.getSort()) - (menu2.getSort()==null?0:menu2.getSort());
        }).collect(Collectors.toList());




        return level1Menus;
    }

    @Override
    public void removeMenuByIds(List<Long> asList) {
        //TODO  1、检查当前删除的菜单，是否被别的地方引用

        //逻辑删除
        baseMapper.deleteBatchIds(asList);
    }

    //[2,25,225]
    @Override
    public Long[] findCatelogPath(Long catelogId) {
        List<Long> paths = new ArrayList<>();
        List<Long> parentPath = findParentPath(catelogId, paths);

        Collections.reverse(parentPath);


        return parentPath.toArray(new Long[parentPath.size()]);
    }

    /**
     * 级联更新所有关联的数据
     * @param category
     */
    @CacheEvict(value ={"catogory"},key = "'getLevel1Categorys'")
    @Transactional
    @Override
    public void updateCascade(CategoryEntity category) {
        this.updateById(category);
        categoryBrandRelationService.updateCategory(category.getCatId(),category.getName());
    }
    //每一个需要缓存的数据我们都来指定要放到哪个名字的缓存（缓存的分区）
    @Cacheable(value = {"catogory"},key = "'getLevel1Categorys'",sync = true)  //代表当前方法结果集需要缓存，如果缓存中有，方法不用调用，如果缓存没有会调用发发，最后将方法的结果放入缓存
    @Override
    public List<CategoryEntity> getLevel1Categorys() {
        List<CategoryEntity> categoryEntities = baseMapper.selectList(new QueryWrapper<CategoryEntity>().eq("parent_cid", 0));
        return categoryEntities;
    }
    //TODO 产生堆外内存溢出: OutOfDirectMemoryError
    //
    //从数据库查询并封装分类数据
    @Override
    public Map<String, List<Catelog2Vo>> getCatalogJson() {
        //给缓存中放json字符串、拿出的json字符串，还用逆转为能用的对象类型；【序列化与反序列化】
        //1、加入缓存逻辑
        String catalogJSON = redisTemplate.opsForValue().get("catalogJSON");


        if(StringUtils.isEmpty(catalogJSON)){
            //2、缓存中没有 查询数据库
            Map<String, List<Catelog2Vo>> catalogJsonFromDb = getCatalogJsonFromDb();
            //把查询来的数据转到成json放到缓存中,json是跨平台,大家都能解析
            String jsonString = JSON.toJSONString(catalogJsonFromDb);
            redisTemplate.opsForValue().set("catalogJSON",jsonString);
            return catalogJsonFromDb;
        }
        Map<String, List<Catelog2Vo>> result=JSON.parseObject(catalogJSON,new TypeReference<Map<String, List<Catelog2Vo>>>(){});


        return result;
    }


    public Map<String, List<Catelog2Vo>> getCatalogJsonFromDb() {

        /**
         * 优化
         * 1、查多次数据库变成查一次
         */
        //TODO 本地锁: synchronized,JUC(Lock)  都是本地锁,在分布式的情况下,想要锁住所有必须用分布式锁
        List<CategoryEntity> selectList = baseMapper.selectList(null);

        //1、查出一级分类
        List<CategoryEntity> level1Categorys = getParent_cid(selectList,0l);
        //封装数据
        Map<String, List<Catelog2Vo>> parent_cid = level1Categorys.stream().collect(Collectors.toMap(k -> k.getCatId().toString(),
                v -> {
                    //当前是一级分类
                    List<CategoryEntity> categoryEntities = getParent_cid(selectList,v.getCatId());
                    //封装成指定Vo
                    List<Catelog2Vo> catelog2Vos = null;
                    if (categoryEntities != null) {
                        catelog2Vos = categoryEntities.stream().map(l2 -> {
                            Catelog2Vo catelog2Vo = new Catelog2Vo(v.getCatId().toString(), null, l2.getCatId().toString(), l2.getName());
                            //找当前二级分类的三级分类封装成 VO
                            List<CategoryEntity> level3Catelog = getParent_cid(selectList,l2.getCatId());
                            if(level3Catelog!=null){
                                List<Catelog2Vo.Catelog3Vo> collect = level3Catelog.stream().map(l3 -> {
                                    //封装成指定格式
                                    Catelog2Vo.Catelog3Vo catelog3Vo = new Catelog2Vo.Catelog3Vo(l2.getCatId().toString(), l3.getCatId().toString(), l3.getName());
                                    return catelog3Vo;
                                }).collect(Collectors.toList());

                                catelog2Vo.setCatalog3List(collect);
                            }
                            return catelog2Vo;
                        }).collect(Collectors.toList());
                    }


                    return catelog2Vos;
                }));

        return parent_cid;
    }

    private List<CategoryEntity> getParent_cid(List<CategoryEntity> selectList,Long parent_cid) {
        List<CategoryEntity> collect = selectList.stream().filter(item -> item.getParentCid() == parent_cid).collect(Collectors.toList());

        return collect;

    }


    //225,25,2
    private List<Long> findParentPath(Long catelogId,List<Long> paths){
        //1、收集当前节点id
        paths.add(catelogId);
        CategoryEntity byId = this.getById(catelogId);
        if(byId.getParentCid()!=0){
            findParentPath(byId.getParentCid(),paths);
        }
        return paths;

    }


    //递归查找所有菜单的子菜单
    private List<CategoryEntity> getChildrens(CategoryEntity root,List<CategoryEntity> all){

        List<CategoryEntity> children = all.stream().filter(categoryEntity -> {
            return categoryEntity.getParentCid() == root.getCatId();
        }).map(categoryEntity -> {
            //1、找到子菜单
            categoryEntity.setChildren(getChildrens(categoryEntity,all));
            return categoryEntity;
        }).sorted((menu1,menu2)->{
            //2、菜单的排序
            return (menu1.getSort()==null?0:menu1.getSort()) - (menu2.getSort()==null?0:menu2.getSort());
        }).collect(Collectors.toList());

        return children;
    }



}